Chondromalacia of the patella is the grating or grinding sensation during extension of the knee. The cause is thought to be related to overuse, trauma and/or abnormal forces on the knee, such as a mildly abnormal alignment of the patella (knee cap) and femur. Symptoms include knee tenderness, pain in the knee after sitting for a prolonged period of time, knee pain that is worse with stairs or getting out of a chair, and a grating sensation in the knee.
Review Date 12/2/2019
Updated by: C. Benjamin Ma, MD, Professor, Chief, Sports Medicine and Shoulder Service, UCSF Department of Orthopaedic Surgery, San Francisco, CA. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.